Monoazo dyestuffs and complex metal compounds thereof



DYESTUFFS AND COMPLEX METAL COMPOUNDS THEREQF Christian Zickendraht,Binningen, and Alfred Fasciati, Bottmingen, Switzerland, assignors toCilia Limited, Basel, Switzerland, a Swiss firm No Drawing. ApplicationJanuary 10, 1955 Serial No. 481,037

Claims priority, application Switzerland January 15, 1954 4 Claims. (Cl.260-147) MONOAZO This invention provides new monoazo-dyestufis of theformula in which R represents a benzene radical which is free fromgroups imparting solubility in water and is bound in the l-position tothe nitrogen atom of the pyrazolone ring and contains an alkyl group inthe 2-position, and in which the benzene nucleus I may containsubstituents not imparting solubility in water.

The invention also provides complex metal compounds, especially complexchromium compounds of these 2120 dyestufis, and a process for makingthese metal compounds by treating an azo dyestufi of the above formulawith an agent yielding metal.

The monoazo-dyestufis of the above formula can be made by coupling adiazotized 2-aminobenzene-1-carboxylic acid, which may containsubstituents not imparting solubility in water, such as a nitro oralkoxy group or a halogen atom, for example, a chlorine atom, with al-phenyl-3-methyl-5-pyrazolone which is free from groups impartingsolubility in water and contains an alkyl group, advantageously an alkylgroup containing two carbon atoms, in the 2-position of the phenylradical bound in the 1'-position to the pyrazolone ring.

As examples of such l-phenyl-3-methyl-5-pyrazolones there may bementioned:

1- (2' 4'-dimethylphenyl) -3-methyl-5-pyrazolone1-(2:6'-dimethylphenyl)-3-methyl-5-pyrazolone 1-2-methyl-6'-chlorophenyl -3-methyl-5-pyrazolone 1 (2 methyl 6methoxyphenyl) 3 methyl -pyrazolone and advantageously1-(2'-methylphenyl)-3-methyl-5-pyrazolone and above alll-(2'-ethylphenyl)-3-methyl-5-pyrazolone As examples of2-aminobenzene-l-carboxylic acids there come into consideration, forexample, 4- or S-nitro 2 aminobenzene 1 carboxylic acid, 4-methoxy-2-aminobenzene-l-carboxylic acid, 5-chloro-2-aminobenzene-l-carboxylicacid and above all 2-amino-1-carboxylic acid itself.

The diazotized Z-aminobenzene-l-carboxylic acid may be coupled with thepyrazolone by methods in themselves known, for example, in a weakly acidto alkaline medium.

After the coupling reaction and for the chroming treatment the dyestutEcan easily be isolated from the coupling mixture by filtration, ifdesired, after the addition of sodium chloride. the dyestuff tometallization in the form of the filter cake without intermediatedrying. In some cases it is It is of advantage to subject possible tocarry out the chroming treatment directly in the coupling mixture, thatis to say, without intermediate separation of the dyestufi.

The new monoazo-dyestuffs are generally sufliciently soluble in water inthe form of alkali compounds to enable them to dye well, for example, bythe single bath chroming process or after-chroming process, fromdyebaths which need contain no or only a small addition of acid.

As agents yielding chromium there may be used, for example, simplechromium salts, such as chromium fluoride, chromium sulfate, chromiumacetate, or complex chromium compounds of aliphatic dicarboxylic acidsor hydroxy-carboxylic acids, or advantageously complex chromiumcompounds or aromatic ortho-hydroxy-carboxylic acids. As examples ofaliphatic dicarboxylic acids or hydroxy-carboxylic acids there may bementioned, inter alia, oxalic acid, lactic acid, glycollic acid, citricacid and especially tartaric acid, and among the aromaticortho-hydroxy-carboxylic acids there may be mentioned, for example,those of the benzene series such as 4-, 5- or6-methyl-1-hydroxybenzeneQ-carbcxylic acid and. above all1-hydroxybenzene-2-carboxylic acid itself.

The treatment with an agent yielding chromium is.

advantageously carried out in such manner that a chromiferous dyestulfsis obtained which contains per mo lecular proportion of dyestuii lessthan one, and ad.

vantageously one half atomic proportion of chromium in complex union.Accordingly, the chroming treatment is advantageously carried out withsuch an agent yielding chromium and by such a method as yield complexchromium compounds of the aforesaid constitution. It is generallydesirable to use less than one atomic proportion of chromium for everymolecular proportion of dyestufif and/or to carry out the chromingtreatment in a weakly acid to alkaline medium.

The conversion of the dyestuifs into their chromium compounds isadvantageously carried out at a raised temperature under atmospheric orsuperatmospheric pressure, for example, at the boiling temperature ofthe reaction mixture, if desired, in the presence of a suitableaddition, for example, in the presence of a salt of an organic acid, abase, an organic solvent or another agent assisting the formation of thecomplex.

The dyestuffs obtained according to the aforementioned process can alsobe prepared according vto a modification of this process by reacting ametal free monoazo dyestufi of the Formula I with a chromium complexcompound of the same dyestufi containing per molecular proportion ofdyestuif about one atomic proportion of chromium in complex union.

The chromium compounds of the dyestuffs of the For mula 1 containing permolecular proportion of dyestufi about one atomic proportion of chromiumin complex union used as starting material in this modification of theprocess are so-called lzl-complexes which can be prepared by usualmethods known in themselves, for examdium, ateordinary or raisedtemperature.

forming metal in an acid medium with an excess of a chromium salt,advantageously a salt of trivalent chromium, such as chromium sulfate orchromium fluoride at boiling temperature or if desired at a temperatureexceeding C. For the conversion of the metal-free dyestuffs into the1:1-complexes it is advisable in general 'to carry out the chroming inthe presence of an organic solvent, such as for example alcohol orformamide.

The reaction of the so-obtained 1:1-chromium complexes with themetal-free dyestuffs is carried out advantageously in an aqueous,neutral to weakly alkalineme- It'is advisable C: as a rule to reactequivalent quantities of the chromiferous 1:1-complex and of themetal-free dyestufi, or to use a certain at the most 20% excess of thechromiferous dyestuff.

The chromium compounds of this invention and modifications thereof arechromium compounds of monoazodyestufis of the general formula in which Rrepresents a benzene radical which is free from groups impartingsolubility in water and is bound in the 1-position to the nitrogen atomof the pyrazolone ring and contains an alkyl group in the 2-position,and in which the benzene nucleus I may contain substituents notimparting solubility in water. Especially valuable are the so-called1:2-chromium compounds of this kind, which contain two molecules ofdyestufi bound to one atom of chromium, and above all those which arenot further substitued in the nucleus 1, and in which the radical R contains as its sole substituents an alkyl group of low molecular weight,for example, an alkyl group containing two carbon atoms.

The new chromiferous dyestulis dissolve surprisingly well in water andin weakly acid aqueous media, and are indeed more soluble than themetal-free dyestuffs from which they have been made. They are suitablefor dyeing and printing a very wide variety oi materials, above all fordyeing animal materials such as silk, leather and especially wool, butthey can also be used for dyeing and printing synthetic fibers of asuperpolyamide or superpolyurethane. Wool dyeings produced with thesechromiferous dyestutfs from weakly alkaline, neutral or weakly acid,advantageously acetic acid, baths are distinguished by their levelcharacter, good properties of wet fastness and very good fastness tolight.

The following examples illustrate the invention, the parts andpercentages being by weight unless otherwise stated and the relationshipof parts by weight to parts by volume being the same as the kilogram tothe liter:

Example 1 13.7 parts of Z-aminobenzened-carboxylic acid are dissolved in60 parts of water and 24 parts of hydrochloric acid of 30 percentstrength and diazotized at -5 C. with an aqueous solution of 6.9 partsof sodium nitrite. The resulting diazo-soiution is added to a solution,cooled to 10-12 (3., of 20.2 parts of1-(2:6'-dimethylphenyD-Z-rnethyl--5-pyrazoione, 50 parts by volume of a2 N-solution of sodium hydroxide, 25 parts by volume of a sodiumcarbonate solution of 30 percent strength and 100 parts of water. Whenthe coupling is finished, the dyestutr' formed is filtered off andwashed with dilute sodium chloride solution.

The filter cake so obtained is stirred in 1000 parts of water, and afterthe addition of 190 parts of a solution of sodium chromosalicylatehaving a chromium content of 2.6 percent, the whole is boiled for 24hours under all) reflux. After cooling the mixture the chromiferousdyestufi is salted out and filtered off and dried in vacuo. It is ayellow-brown powder which dissolves in water with a yellow coloration,and dyes wool from a neutral or acetic acid bath fast yellow tints.

The chroming treatment may also be carried out .as follows:

The filter cake is stirred in 1000 parts of water, and after theaddition of 28 parts of crystalline sodium acetate and 155 parts of achromium fluoride solution having a content of chromium corresponding'to4.9 percent of Cr O the whole is boiled for 24 'hours under reflux. Thechromiferous dyestutf so obtained is filtered'ofi and dried. It hasproperties similar to those of the chromium complex described above.

Similar dyestulfs, which dye wool yellow tints, are obtained by treatingthe monoazo-dyestufis, which are obtainable from the diazo and couplingcomponents mentioned in columns I and II of the following table, with anagent yielding chromium by the methods described above.

I II

coon rr t zont 1 \TH HOC\ /N .L n N C1 -CHa COOH HC-CH: NH noo\ /N 2 wHaC- CH:

coon n o-ons 3 \TH HO-C /LL' coon H%-C-CH; NH no-o /N 4 l Example 2 100parts of well wetted Wool are entered at 40*50" C. into a dyebath whichcontains in 4000 parts of water 1 part of the chromiferous dyestufi?obtainable as described in the first and second paragraphs of Example 1,and 10 parts of crystalline sodium sulfate. 2 parts of acetic acid of 40percent strength are added, the temperature is raised to the boil in thecourse of /a hour, and dyeing is carried on for hour at the boil. TheWool is finally rinsed with cold water and dried. There is obtained ayellow dyeing. The same result is obtained when no acetic acid is addedto the dyebath.

Example 3 100 parts of well wetted wool are entered at 60 C. into adyebath which contains in 4000 parts of water 1 part of the dyestuffobtainable by coupling the components mentioned in item No. 3 of theabove table, 2 parts of acetic acid of 40 percent strength and 10 partsof crystalline sodium sulfate. The temperature is raised to the boil inthe course of 30 minutes and dyeing is carried on at the boil for 45minutes. 5 parts of-sulfuric acid of 10 percent strength are then addedand dyeing is continued for a further 15 minutes. The dyebath is cooledto about C., 1.1 parts of potassium bichromate are added, the bath israised to the boil and chroming is carried out for about 40 minutes atthe boil. The'wool is dyed a yellow tint which is fast to light.

Example 4 A dyebath is prepared with 4000 parts of water, 1.5 parts ofpotassium chromate, 1.5 parts of ammonium sulfate, parts of crystallinesodium sulfate and 1 part of the dyestuff obtainable as described in thefirst paragraph of Example 1. 100 parts of Well wetted wool are enteredinto the dyebath at 60 C., the temperature is raised to the boil in thecourse of 30 minutes, and boiling is maintained for 45 minutes. There isthen added 0.5 part of acetic acid of 40 percent strength and boiling iscontinued for a further 45 minutes. The wool is dyed a fast yellow tint.

What is claimed is:

1. A dyestufi selected from the group consisting of a monoazo dyestutfof the formula COOH C=N (13H: X

wherein X represents a member of the group consisting of a hydrogen anda chlorine atom, and R represents a benzene radical free from groupsimparting solubility in water and bound in the 1-position to thenitrogen atom of the pyrazolone ring, which radical contains in the 2-position an alkyl group containing at most 2 carbon atoms, and a complexchromium compound of said mono azo dyestufi containing one chromium atombound in complex union with substantially two molecules of monoazodyestutf.

2. A complex chromium compound containing one atom of chromium bound incomplex union with substantially two molecules of a monoazo dyestufi ofthe formula wherein n represents a whole number up to 3.

4. The complex chromium compound containing one atom of chromium boundin complex union with substantially two molecules of the monoazodyestulf of the formula References Cited in the file of this patentUNITED STATES PATENTS 2,028,981 Krzikalla et a1. Ian. 28, 1936 2,464,322Krebser et a1. Mar. 15, 1949 2,681,338 Harrison et al. June 15, 1954

1. A DYESTUFF SELECTED FROM THE GROUP CONSISTING OF A MONOAZO DYESTUFFOF THE FORMULA